Synthesis And Primary Biological Activity Tests Of Fluorophenyl-pyrimidinyl Urea Derivatives

Phenyl urea derivatives have been characterized by broad-spectrum of weed control at ultra-low dosage of application, good selectivity and low toxicity. The compounds are composed of 3 parts: aromatic ring, urea bridge and heterocycle. Heterocycle is always pyrimidine or triazine. The substituted groups of aromatic ring are mainly alkyl, alkoxyl, chlorine, while aromatic ring compounds with trifluoromethyl group and fluorine are seldom reported.Aromatic isocyanate was synthesized by aromatic amine and triphosgene, through reaction with pyrilamine to product aim compounds. 13 novel compounds and 2 reported compounds were synthesized. Their structures were comfirmed by IR, MS and ~1HNMR. In this paper, in order to study primary herbicidal activity of compounds on oryza sativa L., rape, echinochloa crusgalli L. and amaranthus albus L., pot experimental method was used in this test. The structures are as follows:The result showed that:In this experiment, the isocyanate method was used, the result showed that the substitution of bis(trichloromethyl)carbonate for phosgene is safe, convenient, environmental friendly, easy to fix on quantity, easy to control.According to the screening procedure of these new compounds, the herbicidal bioactivity tests were taken in the concentration 400mg/L,100mg/L, 10mg/L, 5mg/L, 2.5mg/L. The results showed that the herbicidal activity varied from different species and concentration of novel compounds. Compounds A, D, E, F, H, I, J, K, M, N demonstrated promotional activity at rape and inhibitory activity against the echinochloa crusgalli L. and amaranthus albus L. Compounds C, G demonstrated promotional activity at rape and inhibitory activity against the amaranthus albus L. Compounds J, L, O demonstrated promotional activity at rape and inhibitory activity against the echinochloa crusgalli L. and amaranthus albus L.According to the above results, pyrimidinyl urea compounds have the potential application on herbicidal activity and plant growth regulating activity. Compounds A, D, I, M,O provided excellent herbicidal activity and plant growth regulating effects.These results are valuable for the analysis between structure and biological activity. And it was a basis of further study on the synthesis, structural modification and biological activity for this kind of compounds.